In conventional free space optical communication receivers, focusing optics reduces the field of regard (in the range of millidegree) while increasing the power received by the detector. As a result, a receiver communicates with one transmitter at a time. In this paper, we propose a novel two-metalens-receiver system that offers a wider field of regard (in the range of degrees) to capture the optical signal from a large Angle of Arrival (AoA). The first metalens of the system compresses and separates optical beams, based on different incident angles. The compression factor of the first metalens needs to be chosen based on the receiver system’s overall length, aperture size, and minimum angular separation between the transmitters. The second metalens redirects and focuses the beam to the detector sitting on the optical axis. Physical Optics calculation with the proposed phase profile as a phase mask shows that our proposed system increases the power received by the detector up to 1000 times compared to the conventional system for large AoA. As a result, transmitters with wide angular (and spatial) separation can communicate with the proposed receiver simultaneously. The designed phase profile is implemented by a meta-unit cell with varying diameters of Si nanopillars sitting on the quartz substrate. Finally, Quasi- 3D full wave simulation is carried out to show the effectiveness of the two metalens-receiver systems.
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